girlfriend and "friends"

i strarted dating with my current girlfriend 2 weeks ago. Before I was going out with her, her friend, (whos girl) and two guys. Those guys were my good friends. We were just haging out and things like that...u know....and then i started things with my current girlfriend. We kissed when we were out together with others. My friends started to behave very strange....we were in pub together and i went to the WC. before i left there was silence, and when i got back, my "friends" were talking, but stopped immediately as they saw me coming. and my girlfriend said that they talking about me when am not there that i am f***r and such things. i ve been talking with my gf and we found out this: one of my friends likes her and hes jealous and behaves like that becuz i am dating with her……and her friend (that girl) stopped talking to her because guy she likes doesnt like her, but my girlfriend....how to turn all back....i want to date with my love and go put with my friends...what should i do? P.S. me and those two guys playing football (or soccer) for the same team and we met girls there....they used to visit our matches and then we strated to go out together with them....just for explanation... id appreciate every advice